A new diver can handle a pony. I know, as I did it.
It aint rocket science.
I don't disagree per se, but my thinking is that we should look at each incremental item of gear and ask how far adding it would tip the scales toward too much complexity in total. So a new diver adds a pony and then wants to add something like a drysuit, a camera, a spear, or whatever. A pony, by itself, may not be too much for some newer divers. (It probably would have been for me, but I totally lack natural talent for this stuff.) If the potential problem or other reason that a new item of gear is being considered could be mitigated by some alternative to adding that item, then using the alternative might free up the diver's bandwidth to add yet some other item of gear that is going to see more use. So, for example, if you're set on using a camera, maybe the scales would balance better by omitting the pony that's intended to address an extremely rare event, and instead make sure you're diving with a proper buddy. Less gear means more diver bandwidth (both brain and physical space) for other things. If you have no choice but to team with an insta-buddy, and are choosing to use a pony for that reason, then maybe be judicious about adding other things.